Liquid Crystalline Polymer Composition for Camera Modules

ABSTRACT

A polymer composition that is capable of exhibiting a unique combination of ductility (e.g., tensile elongation at break), impact strength (e.g., Charpy notched impact strength), and dimensional stability is provided. For example, the polymer composition may contain a liquid crystalline polymer in combination with an epoxy-functionalized olefin copolymer and an inorganic particulate material.

RELATED APPLICATIONS

The present application claims priority to U.S. Provisional ApplicationSer. No. 62/205,865, filed on Aug. 17, 2015, which is incorporatedherein in its entirety by reference thereto.

BACKGROUND OF THE INVENTION

Camera modules (or components) are often employed in mobile phones,laptop computers, digital cameras, digital video cameras, etc. Examplesinclude, for instance, compact camera modules that include a carriermounted to a base, digital camera shutter modules, components of digitalcameras, cameras in games, medical cameras, surveillance cameras, etc.Such camera modules have become more complex and now tend to includemore moving parts. In some cases, for example, two compact camera moduleassemblies can be mounted within a single module to improve picturequality (“dual camera” modules). In other cases, an array of compactcamera modules can be employed. As the design of these parts become morecomplex, it is increasingly important that the polymer compositions usedto form the molded parts of camera modules are sufficiently ductile sothat they can survive the assembly process. The polymer compositionsmust also be capable of absorbing a certain degree of impact energyduring use without breaking or chipping. To date, most conventionaltechniques involve the use of fibrous fillers to help improve thestrength and other properties of the polymer composition. Unfortunately,however, these techniques ultimately just lead to other problems, suchas poor dimensional stability of the part when it is heated.

As such, a need exists for an improved polymer composition for use inthe molded parts of camera modules.

SUMMARY OF THE INVENTION

In accordance with one embodiment of the present invention, a polymercomposition is disclosed that comprises 100 parts by weight of at leastone liquid crystalline polymer; from about 50 to about 90 parts byweight of an inorganic particulate material having a hardness value ofabout 2.5 or more based on the Mohs hardness scale and an average sizeof from about 0.1 to about 35 micrometers; and from about 1 to about 15parts by weight of an epoxy-functionalized olefin copolymer.

In accordance with another embodiment of the present invention, a moldedpart for a camera module is disclosed. The molded part comprises apolymer composition that includes a liquid crystalline polymer. Thecomposition exhibits a tensile elongation at break of about 3.5% or moreas determined in accordance with ISO Test No. 527:2012 at 23° C., aCharpy notched impact strength of about 6 kJ/m² or more as determined inaccordance with ISO Test No. 179-1:2010 at 23° C., and a dimensionalstability of about 6 or less as determined in accordance with ISO294-4:2001 using a Type D2 specimen.

Other features and aspects of the present invention are set forth ingreater detail below.

BRIEF DESCRIPTION OF THE FIGURES

A full and enabling disclosure of the present invention, including thebest mode thereof to one skilled in the art, is set forth moreparticularly in the remainder of the specification, including referenceto the accompanying figures, in which:

FIGS. 1-2 are perspective and front views of a compact camera module(“CCM”) that may be formed in accordance with one embodiment of thepresent invention.

DETAILED DESCRIPTION

It is to be understood by one of ordinary skill in the art that thepresent discussion is a description of exemplary embodiments only, andis not intended as limiting the broader aspects of the presentinvention.

Generally speaking, the present invention is directed to a polymercomposition that is capable of exhibiting a unique combination ofductility (e.g., tensile elongation at break) and impact strength (e.g.,Charpy notched impact strength) to enable its use in complex cameramodule designs. For example, the polymer composition may exhibit atensile elongation at break of about 3.5% or more, in some embodimentsabout 4% or more, in some embodiments from about 4.5% to about 20%, andin some embodiments, from about 5% to about 10%, as determined inaccordance with ISO Test No. 527:2012 (technically equivalent to ASTMD638-14 at 23° C. The composition may also possess a Charpy notchedimpact strength of about 6 kJ/m² or more, in some embodiments about 6.5kJ/m² or more, in some embodiments from about 7 to about 25 kJ/m², andin some embodiments, from about 8 to about 20 kJ/m², measured at 23° C.according to ISO Test No. 179-1:2010) (technically equivalent to ASTMD256-10, Method B). Contrary to conventional wisdom, it is has beendiscovered that such a balance of ductility and high impact strength canbe achieved without adversely impacting dimensional stability. Moreparticularly, the composition may exhibit a dimensional stability ofabout 6 or less, in some embodiments about 5 or less, in someembodiments from about 0.5 to about 5, and in some embodiments, fromabout 1 to about 4.5. The “dimensional stability” may be determined bydividing the degree of shrinkage in the transverse direction by thedegree of shrinkage in the machine direction, which may be determined inaccordance with ISO 294-4:2001 using a Type D2 specimen (technicallyequivalent to ASTM D955-08(2014)). The degree of shrinkage in thetransverse direction (“S_(T)”) may, for instance, be from about 0.2% toabout 1.5%, in some embodiments from about 0.4% to about 1.2%, and insome embodiments, from about 0.5% to about 1.0%, while the degree ofshrinkage in the machine direction (“S_(F)”) may be from about 0.02% toabout 0.6%, in some embodiments from 0.05% to about 0.5%, and in someembodiments, from about 0.1% to about 0.4%.

The present inventors have discovered that the ability to achieve a partwith such a unique combination of properties can be achieved throughselective control over the nature of the components employed in thepolymer composition, and their relative concentration. For example, thepolymer composition may contain a liquid crystalline polymer incombination with an epoxy-functionalized olefin copolymer and aninorganic particulate material having a hardness value of about 2.5 ormore, in some embodiments about 3.0 or more, in some embodiments fromabout 3.0 to about 11.0, in some embodiments from about 3.5 to about11.0, and in some embodiments, from about 4.5 to about 6.5 based on theMohs hardness scale. Such materials also typically have a median size(e.g., diameter) of from about 0.1 to about 35 micrometers, in someembodiments from about 2 to about 20 micrometers, in some embodimentsfrom about 3 to about 15 micrometers, and in some embodiments, fromabout 7 to about 12 micrometers, such as determined using laserdiffraction techniques in accordance with ISO 13320:2009 (e.g., with aHoriba LA-960 particle size distribution analyzer). The material mayalso have a narrow size distribution. That is, at least about 70% byvolume of the particles, in some embodiments at least about 80% byvolume of the particle material, and in some embodiments, at least about90% by volume of the material may have a size within the ranges notedabove.

The inorganic particulate material is typically employed in an amount offrom about 50 to about 90 parts, in some embodiments from about 55 toabout 85 parts, and in some embodiments, from about 60 to about 80 partsby weight per 100 parts of the liquid crystalline polymer. Likewise, theepoxy-functionalized olefin copolymer is typically employed in thepolymer composition in an amount of from about 1 to about 15 parts, insome embodiments from about 2 to about 12 parts, and in someembodiments, from about 3 to about 10 parts by weight per 100 parts ofthe liquid crystalline polymer. For example, the inorganic particulatematerial typically constitutes from about 20 wt. % to about 60 wt. %, insome embodiments from about 25 wt. % to about 55 wt. %, and in someembodiments, from about 30 wt. % to about 50 wt. % of the polymercomposition, while the epoxy-functionalized olefin copolymer typicallyconstitutes from about 0.1 wt. % to about 20 wt. %, in some embodimentsfrom about 0.5 wt. % to about 15 wt. %, and in some embodiments, fromabout 1 wt. % to about 10 wt. % of the polymer composition. Liquidcrystalline polymers may also constitute from about 20 wt. % to about 80wt. %, in some embodiments from about 30 wt. % to about 70 wt. %, and insome embodiments, from about 35 wt. % to about 60 wt. % of the polymercomposition.

Various embodiments of the present invention will now be described inmore detail.

I. Liquid Crystalline Polymer

The liquid crystalline polymer employed in the polymer composition isgenerally classified as “thermotropic” to the extent that it can possessa rod-like structure and exhibit a crystalline behavior in their moltenstate (e.g., thermotropic nematic state). The polymer has a relativelyhigh melting temperature, such as from about 250° C. to about 400° C.,in some embodiments from about 280° C. to about 390° C., and in someembodiments, from about 300° C. to about 380° C. Such polymers may beformed from one or more types of repeating units as is known in the art.The liquid crystalline polymer may, for example, contain one or morearomatic ester repeating units, typically in an amount of from about 60mol. % to about 99.9 mol. %, in some embodiments from about 70 mol. % toabout 99.5 mol. %, and in some embodiments, from about 80 mol. % toabout 99 mol. % of the polymer. The aromatic ester repeating units maybe generally represented by the following Formula (I):

wherein,

ring B is a substituted or unsubstituted 6-membered aryl group (e.g.,1,4-phenylene or 1,3-phenylene), a substituted or unsubstituted6-membered aryl group fused to a substituted or unsubstituted 5- or6-membered aryl group (e.g., 2,6-naphthalene), or a substituted orunsubstituted 6-membered aryl group linked to a substituted orunsubstituted 5- or 6-membered aryl group (e.g., 4,4-biphenylene); and

Y₁ and Y₂ are independently O, C(O), NH, C(O)HN, or NHC(O).

Typically, at least one of Y₁ and Y₂ are C(O). Examples of such aromaticester repeating units may include, for instance, aromatic dicarboxylicrepeating units (Y₁ and Y₂ in Formula I are C(O)), aromatichydroxycarboxylic repeating units (Y₁ is O and Y₂ is C(O) in Formula I),as well as various combinations thereof.

Aromatic dicarboxylic repeating units, for instance, may be employedthat are derived from aromatic dicarboxylic acids, such as terephthalicacid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenylether-4,4′-dicarboxylic acid, 1,6-naphthalenedicarboxylic acid,2,7-naphthalenedicarboxylic acid, 4,4′-dicarboxybiphenyl,bis(4-carboxyphenyl)ether, bis(4-carboxyphenyl)butane,bis(4-carboxyphenyl)ethane, bis(3-carboxyphenyl)ether,bis(3-carboxyphenyl)ethane, etc., as well as alkyl, alkoxy, aryl andhalogen substituents thereof, and combinations thereof. Particularlysuitable aromatic dicarboxylic acids may include, for instance,terephthalic acid (“TA”), isophthalic acid (“IA”), and2,6-naphthalenedicarboxylic acid (“NDA”). When employed, repeating unitsderived from aromatic dicarboxylic acids (e.g., IA, TA, and/or NDA)typically constitute from about 5 mol. % to about 60 mol. %, in someembodiments from about 10 mol. % to about 55 mol. %, and in someembodiments, from about 15 mol. % to about 50% of the polymer.

Aromatic hydroxycarboxylic repeating units may also be employed that arederived from aromatic hydroxycarboxylic acids, such as, 4-hydroxybenzoicacid; 4-hydroxy-4′-biphenylcarboxylic acid; 2-hydroxy-6-naphthoic acid;2-hydroxy-5-naphthoic acid; 3-hydroxy-2-naphthoic acid;2-hydroxy-3-naphthoic acid; 4′-hydroxyphenyl-4-benzoic acid;3′-hydroxyphenyl-4-benzoic acid; 4′-hydroxyphenyl-3-benzoic acid, etc.,as well as alkyl, alkoxy, aryl and halogen substituents thereof, andcombination thereof. Particularly suitable aromatic hydroxycarboxylicacids are 4-hydroxybenzoic acid (“HBA”) and 6-hydroxy-2-naphthoic acid(“HNA”). When employed, repeating units derived from hydroxycarboxylicacids (e.g., HBA and/or HNA) typically constitute from about 10 mol. %to about 85 mol. %, in some embodiments from about 20 mol. % to about 80mol. %, and in some embodiments, from about 25 mol. % to about 75% ofthe polymer.

Other repeating units may also be employed in the polymer. In certainembodiments, for instance, repeating units may be employed that arederived from aromatic diols, such as hydroquinone, resorcinol,2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene,1,6-dihydroxynaphthalene, 4,4′-dihydroxybiphenyl (or 4,4′-biphenol),3,3′-dihydroxybiphenyl, 3,4′-dihydroxybiphenyl, 4,4′-dihydroxybiphenylether, bis(4-hydroxyphenyl)ethane, etc., as well as alkyl, alkoxy, aryland halogen substituents thereof, and combinations thereof. Particularlysuitable aromatic diols may include, for instance, hydroquinone (“HQ”)and 4,4′-biphenol (“BP”). When employed, repeating units derived fromaromatic diols (e.g., HQ and/or BP) typically constitute from about 1mol. % to about 30 mol. %, in some embodiments from about 2 mol. % toabout 25 mol. %, and in some embodiments, from about 5 mol. % to about20% of the polymer. Repeating units may also be employed, such as thosederived from aromatic amides (e.g., acetaminophen (“APAP”)) and/oraromatic amines (e.g., 4-aminophenol (“AP”), 3-aminophenol,1,4-phenylenediamine, 1,3-phenylenediamine, etc.). When employed,repeating units derived from aromatic amides (e.g., APAP) and/oraromatic amines (e.g., AP) typically constitute from about 0.1 mol. % toabout 20 mol. %, in some embodiments from about 0.5 mol. % to about 15mol. %, and in some embodiments, from about 1 mol. % to about 10% of thepolymer. It should also be understood that various other monomericrepeating units may be incorporated into the polymer. For instance, incertain embodiments, the polymer may contain one or more repeating unitsderived from non-aromatic monomers, such as aliphatic or cycloaliphatichydroxycarboxylic acids, dicarboxylic acids, diols, amides, amines, etc.Of course, in other embodiments, the polymer may be “wholly aromatic” inthat it lacks repeating units derived from non-aromatic (e.g., aliphaticor cycloaliphatic) monomers.

Although not necessarily required, the liquid crystalline polymer may bea “low naphthenic” polymer to the extent that it contains a minimalcontent of repeating units derived from naphthenic hydroxycarboxylicacids and naphthenic dicarboxylic acids, such asnaphthalene-2,6-dicarboxylic acid (“NDA”), 6-hydroxy-2-naphthoic acid(“HNA”), or combinations thereof. That is, the total amount of repeatingunits derived from naphthenic hydroxycarboxylic and/or dicarboxylicacids (e.g., NDA, HNA, or a combination of HNA and NDA) is typically nomore than 30 mol. %, in some embodiments no more than about 15 mol. %,in some embodiments no more than about 10 mol. %, in some embodiments nomore than about 8 mol. %, and in some embodiments, from 0 mol. % toabout 5 mol. % of the polymer (e.g., 0 mol. %). Despite the absence of ahigh level of conventional naphthenic acids, it is believed that theresulting “low naphthenic” polymers are still capable of exhibiting goodthermal and mechanical properties.

In one particular embodiment, the liquid crystalline polymer may beformed from repeating units derived from 4-hydroxybenzoic acid (“HBA”)and terephthalic acid (“TA”) and/or isophthalic acid (“IA”), as well asvarious other optional constituents. The repeating units derived from4-hydroxybenzoic acid (“HBA”) may constitute from about 10 mol. % toabout 80 mol. %, in some embodiments from about 30 mol. % to about 75mol. %, and in some embodiments, from about 45 mol. % to about 70% ofthe polymer. The repeating units derived from terephthalic acid (“TA”)and/or isophthalic acid (“IA”) may likewise constitute from about 5 mol.% to about 40 mol. %, in some embodiments from about 10 mol. % to about35 mol. %, and in some embodiments, from about 15 mol. % to about 35% ofthe polymer. Repeating units may also be employed that are derived from4,4′-biphenol (“BP”) and/or hydroquinone (“HQ”) in an amount from about1 mol. % to about 30 mol. %, in some embodiments from about 2 mol. % toabout 25 mol. %, and in some embodiments, from about 5 mol. % to about20% of the polymer. Other possible repeating units may include thosederived from 6-hydroxy-2-naphthoic acid (“HNA”),2,6-naphthalenedicarboxylic acid (“NDA”), and/or acetaminophen (“APAP”).In certain embodiments, for example, repeating units derived from HNA,NDA, and/or APAP may each constitute from about 1 mol. % to about 35mol. %, in some embodiments from about 2 mol. % to about 30 mol. %, andin some embodiments, from about 3 mol. % to about 25 mol. % whenemployed.

II. Inorganic Particulate Material

As noted above, an inorganic particulate material having a certainhardness value may be employed in the polymer composition. Examples ofsuch a particulate material may include, for instance, carbonates, suchas calcium carbonate (CaCO₃, Mohs hardness of 3.0) or a copper carbonatehydroxide (Cu₂CO₃(OH)₂, Mohs hardness of 4.0); fluorides, such ascalcium fluoride (CaFl₂, Mohs hardness of 4.0); phosphates, such ascalcium pyrophosphate ((Ca₂P₂O₇, Mohs hardness of 5.0), anhydrousdicalcium phosphate (CaHPO₄, Mohs hardness of 3.5), or hydrated aluminumphosphate (AlPO₄.2H₂O, Mohs hardness of 4.5); silicates, such as silica(SiO₂, Mohs hardness of 6.0), potassium aluminum silicate (KAlSi₃O₈,Mohs hardness of 6), or copper silicate (CuSiO₃.H₂O, Mohs hardness of5.0); borates, such as calcium borosilicate hydroxide (Ca₂B₅SiO₉(OH)₅,Mohs hardness of 3.5); alumina (AlO₂, Mohs hardness of 10.0); sulfates,such as calcium sulfate (CaSO₄, Mohs hardness of 3.5) or barium sulfate(BaSO₄, Mohs hardness of from 3 to 3.5); and so forth, as well ascombinations thereof.

III. Epoxy-Functionalized Olefin Copolymer

As stated above, an olefin copolymer is also employed that is“epoxy-functionalized” in that it contains, on average, two or moreepoxy functional groups per molecule. The copolymer generally containsan olefinic monomeric unit that is derived from one or more α-olefins.Examples of such monomers include, for instance, linear and/or branchedα-olefins having from 2 to 20 carbon atoms and typically from 2 to 8carbon atoms. Specific examples include ethylene, propylene, 1-butene;3-methyl-1-butene; 3,3-dimethyl-1-butene; 1-pentene; 1-pentene with oneor more methyl, ethyl or propyl substituents; 1-hexene with one or moremethyl, ethyl or propyl substituents; 1-heptene with one or more methyl,ethyl or propyl substituents; 1-octene with one or more methyl, ethyl orpropyl substituents; 1-nonene with one or more methyl, ethyl or propylsubstituents; ethyl, methyl or dimethyl-substituted 1-decene;1-dodecene; and styrene. Particularly desired α-olefin monomers areethylene and propylene. The copolymer may also contain anepoxy-functional monomeric unit. One example of such a unit is anepoxy-functional (meth)acrylic monomeric component. As used herein, theterm “(meth)acrylic” includes acrylic and methacrylic monomers, as wellas salts or esters thereof, such as acrylate and methacrylate monomers.For example, suitable epoxy-functional (meth)acrylic monomers mayinclude, but are not limited to, those containing 1,2-epoxy groups, suchas glycidyl acrylate and glycidyl methacrylate. Other suitableepoxy-functional monomers include allyl glycidyl ether, glycidylethacrylate, and glycidyl itoconate. Other suitable monomers may also beemployed to help achieve the desired molecular weight.

Of course, the copolymer may also contain other monomeric units as isknown in the art. For example, another suitable monomer may include a(meth)acrylic monomer that is not epoxy-functional. Examples of such(meth)acrylic monomers may include methyl acrylate, ethyl acrylate,n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, s-butylacrylate, i-butyl acrylate, t-butyl acrylate, n-amyl acrylate, i-amylacrylate, isobornyl acrylate, n-hexyl acrylate, 2-ethylbutyl acrylate,2-ethylhexyl acrylate, n-octyl acrylate, n-decyl acrylate,methylcyclohexyl acrylate, cyclopentyl acrylate, cyclohexyl acrylate,methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate,n-propyl methacrylate, n-butyl methacrylate, i-propyl methacrylate,i-butyl methacrylate, n-amyl methacrylate, n-hexyl methacrylate, i-amylmethacrylate, s-butyl-methacrylate, t-butyl methacrylate, 2-ethylbutylmethacrylate, methylcyclohexyl methacrylate, cinnamyl methacrylate,crotyl methacrylate, cyclohexyl methacrylate, cyclopentyl methacrylate,2-ethoxyethyl methacrylate, isobornyl methacrylate, etc., as well ascombinations thereof. In one particular embodiment, for example, thecopolymer may be a terpolymer formed from an epoxy-functional(meth)acrylic monomeric component, α-olefin monomeric component, andnon-epoxy functional (meth)acrylic monomeric component. The copolymermay, for instance, be poly(ethylene-co-butylacrylate-co-glycidylmethacrylate), which has the following structure:

wherein, x, y, and z are 1 or greater.

The relative portion of the monomeric component(s) may be selected toachieve a balance between epoxy-reactivity and melt flow rate. Moreparticularly, high epoxy monomer contents can result in good reactivitywith the matrix polymer, but too high of a content may reduce the meltflow rate to such an extent that the copolymer adversely impacts themelt strength of the polymer blend. Thus, in most embodiments, theepoxy-functional (meth)acrylic monomer(s) constitute from about 1 wt. %to about 20 wt. %, in some embodiments from about 2 wt. % to about 15wt. %, and in some embodiments, from about 3 wt. % to about 10 wt. % ofthe copolymer. The α-olefin monomer(s) may likewise constitute fromabout 55 wt. % to about 95 wt. %, in some embodiments from about 60 wt.% to about 90 wt. %, and in some embodiments, from about 65 wt. % toabout 85 wt. % of the copolymer. When employed, other monomericcomponents (e.g., non-epoxy functional (meth)acrylic monomers) mayconstitute from about 5 wt. % to about 35 wt. %, in some embodimentsfrom about 8 wt. % to about 30 wt. %, and in some embodiments, fromabout 10 wt. % to about 25 wt. % of the copolymer. The result melt flowrate is typically from about 1 to about 30 grams per 10 minutes (“g/10min”), in some embodiments from about 2 to about 20 g/10 min, and insome embodiments, from about 3 to about 15 g/10 min, as determined inaccordance with ASTM D1238-13 at a load of 2.16 kg and temperature of190° C.

One example of a suitable epoxy-functionalized copolymer that may beused in the present invention is commercially available from Arkemaunder the name LOTADER® AX8840. LOTADER® AX8840, for instance, has amelt flow rate of 5 g/10 min and has a glycidyl methacrylate monomercontent of 8 wt. %. Another suitable copolymer is commercially availablefrom DuPont under the name ELVALOY® PTW, which is a terpolymer ofethylene, butyl acrylate, and glycidyl methacrylate and has a melt flowrate of 12 g/10 min and a glycidyl methacrylate monomer content of 4 wt.% to 5 wt. %.

IV. Electrically Conductive Filler

Although optional, an electrically conductive filler may also beemployed in the polymer composition to help reduce the tendency tocreate a static electric charge during a molding operation,transportation, collection, assembly, etc. In fact, the presence of acontrolled size and amount of the inorganic particulate material, asnoted above, can enhance the ability of the conductive filler to bedispersed within the liquid crystalline polymer matrix, thereby allowingallow for the use of relatively low concentrations of the conductivefiller to achieve the desired antistatic properties. Because it isemployed in relatively low concentrations, however, the impact onthermal and mechanical properties can be minimized. In this regard,conductive fillers, when employed, typically constitute from about 0.1wt. % to about 30 wt. %, in some embodiments from about 0.3 wt. % toabout 20 wt. %, in some embodiments from about 0.4 wt. % to about 5 wt.%, and in some embodiments, from about 0.5 wt. % to about 1.5 wt. % ofthe polymer composition.

Any of a variety of conductive fillers may generally be employed in thepolymer composition to help improve its antistatic characteristics.Examples of suitable conductive fillers may include, for instance, metalparticles (e.g., aluminum flakes), metal fibers, carbon particles (e.g.,graphite, expanded graphite, grapheme, carbon black, graphitized carbonblack, etc.), carbon nanotubes, carbon fibers, and so forth. Carbonfibers and carbon particles (e.g., graphite) are particularly suitable.When employed, suitable carbon fibers may include pitch-based carbon(e.g., tar pitch), polyacrylonitrile-based carbon, metal-coated carbon,etc. Desirably, the carbon fibers have a high purity in that theypossess a relatively high carbon content, such as a carbon content ofabout 85 wt. % or more, in some embodiments about 90 wt. % or more, andin some embodiments, about 93 wt. % or more. For instance, the carboncontent can be at least about 94% wt., such as at least about 95% wt.,such as at least about 96% wt., such at least about 97% wt., such aseven at least about 98% wt. The carbon purity is generally less than 100wt. %, such as less than about 99 wt. %. The density of the carbonfibers is typically from about 0.5 to about 3.0 g/cm³, in someembodiments from about 1.0 to about 2.5 g/cm³, and in some embodiments,from about 1.5 to about 2.0 g/cm³.

In one embodiment, the carbon fibers are incorporated into the matrixwith minimal fiber breakage. The volume average length of the fibersafter molding can generally be from about 0.1 mm to about 1 mm even whenusing a fiber having an initial length of about 3 mm. The average lengthand distribution of the carbon fibers can also be selectively controlledin the final polymer composition to achieve a better connection andelectrical pathway within the liquid crystalline polymer matrix. Theaverage diameter of the fibers can be from about 0.5 to about 30micrometers, in some embodiments from about 1 to about 20 micrometers,and in some embodiments, from about 3 to about 15 micrometers.

To improve dispersion within the polymer matrix, the carbon fibers maybe at least partially coated with a sizing agent that increases thecompatibility of the carbon fibers with the liquid crystalline polymer.The sizing agent may be stable so that it does not thermally degrade attemperatures at which the liquid crystalline polymer is molded. In oneembodiment, the sizing agent may include a polymer, such as an aromaticpolymer. For instance, the aromatic polymer may have a thermaldecomposition temperature of greater than about 300° C., such as greaterthan about 350° C., such as greater than about 400° C. As used herein,the thermal decomposition temperature of a material is the temperatureat which the material losses 5% of its mass during thermogravimetericanalysis as determined in accordance with ASTM Test E 1131 (or ISO Test11358). The sizing agent can also have a relatively high glasstransition temperature. For instance, the glass transition temperatureof the sizing agent can be greater than about 300° C., such as greaterthan about 350° C., such as greater than about 400° C. Particularexamples of sizing agents include polyimide polymers, aromatic polyesterpolymers including wholly aromatic polyester polymers, and hightemperature epoxy polymers. In one embodiment, the sizing agent mayinclude a liquid crystalline polymer. The sizing agent can be present onthe fibers in an amount of at least about 0.1% wt., such as in an amountof at least 0.2% wt., such as in an amount of at least about 0.1% wt.The sizing agent is generally present in an amount less than about 5%wt., such as in an amount of less than about 3% wt.

Another suitable conductive filler is an ionic liquid. One benefit ofsuch a material is that, in addition to being electrically conductive,the ionic liquid can also exist in liquid form during melt processing,which allows it to be more uniformly blended within the liquidcrystalline polymer matrix. This improves electrical connectivity andthereby enhances the ability of the composition to rapidly dissipatestatic electric charges from its surface.

The ionic liquid is generally a salt that has a low enough meltingtemperature so that it can be in the form of a liquid when meltprocessed with the liquid crystalline polymer. For example, the meltingtemperature of the ionic liquid may be about 400° C. or less, in someembodiments about 350° C. or less, in some embodiments from about 1° C.to about 100° C., and in some embodiments, from about 5° C. to about 50°C. The salt contains a cationic species and counterion. The cationicspecies contains a compound having at least one heteroatom (e.g.,nitrogen or phosphorous) as a “cationic center.” Examples of suchheteroatomic compounds include, for instance, quaternary oniums havingthe following structures:

wherein, R¹, R², R³, R⁴, R⁵, R⁶, R⁷, and R⁸ are independently selectedfrom the group consisting of hydrogen; substituted or unsubstitutedC₁-C₁₀ alkyl groups (e.g., methyl, ethyl, n-propyl, isopropyl, n-butyl,isobutyl, sec-butyl, tert-butyl, n-pentyl, etc.); substituted orunsubstituted C₃-C₁₄ cycloalkyl groups (e.g., adamantyl, cyclopropyl,cyclobutyl, cyclopentyl, cyclooctyl, cyclohexenyl, etc.); substituted orunsubstituted C₁-C₁₀ alkenyl groups (e.g., ethylene, propylene,2-methypropylene, pentylene, etc.); substituted or unsubstituted C₂-C₁₀alkynyl groups (e.g., ethynyl, propynyl, etc.); substituted orunsubstituted C₁-C₁₀ alkoxy groups (e.g., methoxy, ethoxy, n-propoxy,isopropoxy, n-butoxy, t-butoxy, sec-butoxy, n-pentoxy, etc.);substituted or unsubstituted acyloxy groups (e.g., methacryloxy,methacryloxyethyl, etc.); substituted or unsubstituted aryl groups(e.g., phenyl); substituted or unsubstituted heteroaryl groups (e.g.,pyridyl, furanyl, thienyl, thiazolyl, isothiazolyl, triazolyl,imidazolyl, isoxazolyl, pyrrolyl, pyrazolyl, pyridazinyl, pyrimidinyl,quinolyl, etc.); and so forth. In one particular embodiment, forexample, the cationic species may be an ammonium compound having thestructure N⁺R¹R²R³R⁴, wherein R¹, R², and/or R³ are independently aC₁-C₆ alkyl (e.g., methyl, ethyl, butyl, etc.) and R⁴ is hydrogen or aC₁-C₄ alkyl group (e.g., methyl or ethyl). For example, the cationiccomponent may be tri-butylmethylammonium, wherein R¹, R², and R³ arebutyl and R⁴ is methyl.

Suitable counterions for the cationic species may include, for example,halogens (e.g., chloride, bromide, iodide, etc.); sulfates or sulfonates(e.g., methyl sulfate, ethyl sulfate, butyl sulfate, hexyl sulfate,octyl sulfate, hydrogen sulfate, methane sulfonate, dodecylbenzenesulfonate, dodecylsulfate, trifluoromethane sulfonate,heptadecafluorooctanesulfonate, sodium dodecylethoxysulfate, etc.);sulfosuccinates; amides (e.g., dicyanamide); imides (e.g.,bis(pentafluoroethyl-sulfonyl)imide, bis(trifluoromethylsulfonyl)imide,bis(trifluoromethyl)imide, etc.); borates (e.g., tetrafluoroborate,tetracyanoborate, bis[oxalato]borate, bis[salicylato]borate, etc.);phosphates or phosphinates (e.g., hexafluorophosphate, diethylphosphate,bis(pentafluoroethyl)phosphinate,tris(pentafluoroethyl)-trifluorophosphate,tris(nonafluorobutyl)trifluorophosphate, etc.); antimonates (e.g.,hexafluoroantimonate); aluminates (e.g., tetrachloroaluminate); fattyacid carboxylates (e.g., oleate, isostearate, pentadecafluorooctanoate,etc.); cyanates; acetates; and so forth, as well as combinations of anyof the foregoing. To help improve compatibility with the liquidcrystalline polymer, it may be desired to select a counterion that isgenerally hydrophobic in nature, such as imides, fatty acidcarboxylates, etc. Particularly suitable hydrophobic counterions mayinclude, for instance, bis(pentafluoroethylsulfonyl)imide,bis(trifluoromethylsulfonyl)imide, and bis(trifluoromethyl)imide.

V. Other Components

A wide variety of additional additives can also be included in thepolymer composition, such as lubricants, thermally conductive fillers,pigments, antioxidants, stabilizers, surfactants, waxes, flameretardants, anti-drip additives, and other materials added to enhanceproperties and processability. Lubricants, for example, may be employedin the polymer composition that are capable of withstanding theprocessing conditions of the liquid crystalline polymer withoutsubstantial decomposition. Examples of such lubricants include fattyacids esters, the salts thereof, esters, fatty acid amides, organicphosphate esters, and hydrocarbon waxes of the type commonly used aslubricants in the processing of engineering plastic materials, includingmixtures thereof. Suitable fatty acids typically have a backbone carbonchain of from about 12 to about 60 carbon atoms, such as myristic acid,palmitic acid, stearic acid, arachic acid, montanic acid, octadecinicacid, parinric acid, and so forth. Suitable esters include fatty acidesters, fatty alcohol esters, wax esters, glycerol esters, glycol estersand complex esters. Fatty acid amides include fatty primary amides,fatty secondary amides, methylene and ethylene bisamides andalkanolamides such as, for example, palmitic acid amide, stearic acidamide, oleic acid amide, N,N′-ethylenebisstearamide and so forth. Alsosuitable are the metal salts of fatty acids such as calcium stearate,zinc stearate, magnesium stearate, and so forth; hydrocarbon waxes,including paraffin waxes, polyolefin and oxidized polyolefin waxes, andmicrocrystalline waxes. Particularly suitable lubricants are acids,salts, or amides of stearic acid, such as pentaerythritol tetrastearate,calcium stearate, or N,N′-ethylenebisstearamide. When employed, thelubricant(s) typically constitute from about 0.05 wt. % to about 1.5 wt.%, and in some embodiments, from about 0.1 wt. % to about 0.5 wt. % (byweight) of the polymer composition.

As noted above, one beneficial aspect of the present invention is thatgood mechanical properties may be achieved without adversely impactingthe dimensional stability of the resulting part. To help ensure thatthis dimensional stability is maintained, it is generally desirable thatthe polymer composition remains substantially free of conventionalfibrous fillers, such as glass fibers and mineral fibers. Thus, ifemployed at all, such fibers typically constitute no more than about 10wt. %, in some embodiments no more than about 5 wt. %, and in someembodiments, from about 0.001 wt. % to about 3 wt. % of the polymercomposition.

VI. Formation

The liquid crystalline polymer, inorganic particulate material,epoxy-functionalized olefin copolymer, and other optional additives maybe melt processed or blended together. The components may be suppliedseparately or in combination to an extruder that includes at least onescrew rotatably mounted and received within a barrel (e.g., cylindricalbarrel) and may define a feed section and a melting section locateddownstream from the feed section along the length of the screw. Theextruder may be a single screw or twin screw extruder. If desired, theinorganic particulate material and epoxy-functionalized olefin copolymercan be added to the extruder a location downstream from the point atwhich the liquid crystalline polymer is supplied. The speed of the screwmay be selected to achieve the desired residence time, shear rate, meltprocessing temperature, etc. For example, the screw speed may range fromabout 50 to about 800 revolutions per minute (“rpm”), in someembodiments from about 70 to about 150 rpm, and in some embodiments,from about 80 to about 120 rpm. The apparent shear rate during meltblending may also range from about 100 seconds⁻¹ to about 10,000seconds⁻¹, in some embodiments from about 500 seconds⁻¹ to about 5000seconds⁻¹, and in some embodiments, from about 800 seconds⁻¹ to about1200 seconds⁻¹. The apparent shear rate is equal to 4Q/πR³, where Q isthe volumetric flow rate (“m³/s”) of the polymer melt and R is theradius (“m”) of the capillary (e.g., extruder die) through which themelted polymer flows.

Regardless of the particular manner in which it is formed, the presentinventors have discovered that the resulting polymer composition canpossess excellent thermal properties. For example, the melt viscosity ofthe polymer composition may be low enough so that it can readily flowinto the cavity of a mold having small dimensions. In one particularembodiment, the polymer composition may have a melt viscosity of fromabout 1 to about 200 Pa-s, in some embodiments from about 5 to about 180Pa-s, in some embodiments from about 10 to about 150 Pa-s, and in someembodiments, from about 20 to about 120 Pa-s, determined at a shear rateof 1000 seconds⁻¹. Melt viscosity may be determined in accordance withISO Test No. 11443:2005 at a temperature that is 15° C. higher than themelting temperature of the composition (e.g., 350° C.).

VII. Molded Parts

Once formed, the polymer composition may be molded into a shaped part.For example, the shaped part may be molded using a one-componentinjection molding process in which dried and preheated plastic granulesare injected into the mold. Regardless of the technique employed, it hasbeen discovered that the molded part of the present invention may have arelatively smooth surface, which may be represented by its surfaceglossiness). For example, the surface glossiness as determined using agloss meter at an angle of from about 80° to about 85° may be about 35%or more, in some embodiments about 38% or more, and in some embodiments,from about 40% to about 60%. Conventionally, it was believed that partshaving such a smooth surface would not also possess sufficiently goodmechanical properties. Contrary to conventional thought, however, themolded part of the present invention has been found to possess excellentmechanical properties. For example, the part may possess a high weldstrength, which is useful when forming the thin part of a camera module.For example, the part may exhibit a weld strength of from about 10kilopascals (“kPa”) to about 100 kPa, in some embodiments from about 20kPa to about 80 kPa, and in some embodiments, from about 40 kPa to about70 kPa, which is the peak stress as determined in accordance with ISOTest No. 527-1:2012 (technically equivalent to ASTM D638-14) at 23° C.

The tensile and flexural mechanical properties are also good. Forexample, the part may exhibit a tensile strength of from about 20 toabout 500 MPa, in some embodiments from about 50 to about 400 MPa, andin some embodiments, from about 60 to about 350 MPa and/or a tensilemodulus of from about 4,000 MPa to about 20,000 MPa, in some embodimentsfrom about 5,000 MPa to about 18,000 MPa, and in some embodiments, fromabout 6,000 MPa to about 12,000 MPa. The tensile properties may bedetermined in accordance with ISO Test No. 527:2012 (technicallyequivalent to ASTM D638-14) at 23° C. The part may also exhibit aflexural strength of from about 20 to about 500 MPa, in some embodimentsfrom about 50 to about 400 MPa, and in some embodiments, from about 80to about 350 MPa and/or a flexural modulus of from about 4,000 MPa toabout 20,000 MPa, in some embodiments from about 5,000 MPa to about18,000 MPa, and in some embodiments, from about 6,000 MPa to about15,000 MPa. The flexural properties may be determined in accordance withISO Test No. 178:2010 (technically equivalent to ASTM D790-10) at 23° C.The molded part may also exhibit a deflection temperature under load(DTUL) of about 190° C. or more, and in some embodiments, from about200° C. to about 280° C., as measured according to ASTM D648-07(technically equivalent to ISO Test No. 75-2:2013) at a specified loadof 1.8 MPa. The Rockwell hardness of the part may also be about 25 ormore, some embodiments about 30 or more, and in some embodiments, fromabout 35 to about 80, as determined in accordance with ASTM D785-08(Scale M).

In addition, the molded part can also have excellent antistaticbehavior, particularly when a conductive filler is included within thepolymer composition as discussed above. Such antistatic behavior can becharacterized by a relatively low surface and/or volume resistivity asdetermined in accordance with IEC 60093. For example, the molded partmay exhibit a surface resistivity of about 1×10¹⁵ ohms or less, in someembodiments about 1×10¹⁴ ohms or less, in some embodiments from about1×10¹⁰ ohms to about 9×10¹³ ohms, and in some embodiments, from about1×10¹¹ to about 1×10¹³ ohms. Likewise, the molded part may also exhibita volume resistivity of about 1×10¹⁵ ohm-m or less, in some embodimentsfrom about 1×10⁹ ohm-m to about 9×10¹⁴ ohm-m, and in some embodiments,from about 1×10¹⁰ to about 5×10¹⁴ ohm-m. Of course, such antistaticbehavior is by no means required. For example, in some embodiments, themolded part may exhibit a relatively high surface resistivity, such asabout 1×10¹⁵ ohms or more, in some embodiments about 1×10¹⁶ ohms ormore, in some embodiments from about 1×10¹⁷ ohms to about 9×10³⁰ ohms,and in some embodiments, from about 1×10¹⁸ to about 1×10²⁶ ohms.

In certain applications, the molded part may be joined together with oneor more additional components (e.g., molded parts, metals, etc.).Notably, the enhanced ductility of the molded part of the presentinvention can allow it to be readily joined together with anothercomponent using techniques not previously thought possible. In oneembodiment, for example, a heat staking technique may be employed. Insuch embodiments, a plurality of receiving holes may initially be formedin adjacent components, such as around the periphery of the components,and a plurality of heat-stakes may thereafter be inserted intocorresponding receiving holes. Once inserted, a staking device may beused to subject the heating stakes to heat and pressure so that theyeffectively join together the adjacent components. Of course, apart fromheat staking, other known techniques can also be employed, such asadhesive bonding, welding, etc.

VIII. Applications

The polymer composition and/or shaped molded part can be used in avariety of applications. For example, the molded part can be employed inlighting assemblies, battery systems, sensors and electronic components,portable electronic devices such as smart phones, MP3 players, mobilephones, computers, televisions, automotive parts, etc. In one particularembodiment, the molded part may be employed in a camera module, such asthose commonly employed in wireless communication devices (e.g.,cellular telephone). For example, the camera module may employ a base,carrier assembly mounted on the base, a cover mounted on the carrierassembly, etc. The base may have a thickness of about 500 micrometers orless, in some embodiments from about 10 to about 450 micrometers, and insome embodiments, from about 20 to about 400 micrometers. Likewise, thecarrier assembly may have a wall thickness of about 500 micrometers orless, in some embodiments from about 10 to about 450 micrometers, and insome embodiments, from about 20 to about 400 micrometers.

One particularly suitable camera module is shown in FIGS. 1-2. As shown,a camera module 500 contains a carrier assembly 504 that overlies a base506. The base 506, in turn, overlies an optional main board 508. Due totheir relatively thin nature, the base 506 and/or main board 508 areparticularly suited to be molded from the polymer composition of thepresent invention as described above. The carrier assembly 504 may haveany of a variety of configurations as is known in the art. In oneembodiment, for example, the carrier assembly 504 may contain a hollowbarrel that houses one or more lenses 604, which are in communicationwith an image sensor 602 positioned on the main board 508 and controlledby a circuit 601. The barrel may have any of a variety of shapes, suchas rectangular, cylindrical, etc. In certain embodiments, the barrel maybe formed from the polymer composition of the present invention and havea wall thickness within the ranges noted above. It should be understoodthat other parts of the camera module may also be formed from thepolymer composition of the present invention. For example, as shown, acover may overly the carrier assembly 504 that includes, for example, asubstrate 510 (e.g., film) and/or thermal insulating cap 502. In someembodiments, the substrate 510 and/or cap 502 may also be formed fromthe polymer composition.

The present invention may be better understood with reference to thefollowing examples.

Test Methods

Melt Viscosity:

The melt viscosity (Pa-s) may be determined in accordance with ISO TestNo. 11443:2005 at a shear rate of 1000 s⁻¹ and temperature 15° C. abovethe melting temperature (e.g., 350° C.) using a Dynisco LCR7001capillary rheometer. The rheometer orifice (die) had a diameter of 1 mm,length of 20 mm, L/D ratio of 20.1, and an entrance angle of 180°. Thediameter of the barrel was 9.55 mm+0.005 mm and the length of the rodwas 233.4 mm.

Melting Temperature:

The melting temperature (“Tm”) may be determined by differentialscanning calorimetry (“DSC”) as is known in the art. The meltingtemperature is the differential scanning calorimetry (DSC) peak melttemperature as determined by ISO Test No. 11357-2:2013. Under the DSCprocedure, samples were heated and cooled at 20° C. per minute as statedin ISO Standard 10350 using DSC measurements conducted on a TA Q2000Instrument.

Deflection Temperature Under Load (“DTUL”):

The deflection under load temperature may be determined in accordancewith ISO Test No. 75-2:2013 (technically equivalent to ASTM D648-07).More particularly, a test strip sample having a length of 80 mm,thickness of 10 mm, and width of 4 mm may be subjected to an edgewisethree-point bending test in which the specified load (maximum outerfibers stress) was 1.8 Megapascals. The specimen may be lowered into asilicone oil bath where the temperature is raised at 2° C. per minuteuntil it deflects 0.25 mm (0.32 mm for ISO Test No. 75-2:2013).

Tensile Modulus, Tensile Stress, and Tensile Elongation at Break:

Tensile properties may be tested according to ISO Test No. 527:2012(technically equivalent to ASTM D638-14). Modulus and strengthmeasurements may be made on the same test strip sample having a lengthof 80 mm, thickness of 10 mm, and width of 4 mm. The testing temperaturemay be 23° C., and the testing speeds may be 1 or 5 mm/min.

Flexural Modulus and Flexural Stress:

Flexural properties may be tested according to ISO Test No. 178:2010(technically equivalent to ASTM D790-10). This test may be performed ona 64 mm support span. Tests may be run on the center portions of uncutISO 3167 multi-purpose bars. The testing temperature may be 23° C. andthe testing speed may be 2 mm/min.

Notched Charpy Impact Strength:

Notched Charpy properties may be tested according to ISO Test No. ISO179-1:2010) (technically equivalent to ASTM D256-10, Method B). Thistest may be run using a Type A notch (0.25 mm base radius) and Type 1specimen size (length of 80 mm, width of 10 mm, and thickness of 4 mm).Specimens may be cut from the center of a multi-purpose bar using asingle tooth milling machine. The testing temperature may be 23° C.

Rockwell Hardness:

Rockwell hardness is a measure of the indentation resistance of amaterial and may be determined in accordance with ASTM D785-08 (ScaleM). Testing is performed by first forcing a steel ball indentor into thesurface of a material using a specified minor load. The load is thenincreased to a specified major load and decreased back to the originalminor load. The Rockwell hardness is a measure of the net increase indepth of the indentor, and is calculated by subtracting the penetrationdivided by the scale division from 130.

Dimensional Stability:

The degree of shrinkage of a sample in a given direction may bedetermined in accordance with ISO 294-4:2001 (technically equivalent toASTM D955-08(2014)). For example, parts may be injection molded with amold cavity having a machine direction dimension or length (L_(m)) of 60mm, a transverse dimension or width (W_(m)) of 60 mm, and a heightdimension (H_(m)) of 2 mm, which conforms to a Type D2 specimen. Theaverage length (L_(a)) and width (W_(s)) of five (5) test specimens maybe measured after removal from the mold and cooling. The shrinkage inthe flow (or length) direction (S_(F)) may be calculated byS_(F)=(L_(m)−L_(s))×100/L_(m), and the shrinkage in the transverse (orwidth) direction (S_(T)) may be calculated byS_(w)=(W_(m)−W_(s))×100/W_(m). The “dimensional stability” maythereafter be determined by dividing the degree of shrinkage in thetransverse direction by the degree of shrinkage in the machinedirection.

Surface/Volume Resistivity:

The surface and volume resistivity values may be determined inaccordance with IEC 60093 (equivalent to ASTM D257-07). According tothis procedure, a standard specimen (e.g., 1 meter cube) is placedbetween two electrodes. A voltage is applied for sixty (60) seconds andthe resistance is measured. The surface resistivity is the quotient ofthe potential gradient (in V/m) and the current per unit of electrodelength (in A/m), and generally represents the resistance to leakagecurrent along the surface of an insulating material. Because the four(4) ends of the electrodes define a square, the lengths in the quotientcancel and surface resistivities are reported in ohms, although it isalso common to see the more descriptive unit of ohms per square. Volumeresistivity is also determined as the ratio of the potential gradientparallel to the current in a material to the current density. In SIunits, volume resistivity is numerically equal to the direct-currentresistance between opposite faces of a one-meter cube of the material(ohm-m).

Example 1

Samples 1-2 are formed from various percentages of a liquid crystallinepolymer, barium sulfate, epoxy-functionalized olefin copolymer,lubricant (Glycolube™ P), conductive filler, and black colormasterbatch, as indicated in Table 1 below. The epoxy-functionalizedolefin copolymer is a terpolymer formed from ethylene, butyl acrylate,and glycidyl methacrylate (Elvaloy® PTW, DuPont). The barium sulfate hasa median diameter of about 4 micrometers. The black color masterbatchcontains 80 wt. % liquid crystalline polymer and 20 wt. % carbon black.The conductive filler includes an ionic liquid—i.e.,tri-n-butylmethylammonium bis(trifluoromethanesulfonyl)-imide (FC-4400from 3M). The liquid crystalline polymer in each of the samples isformed from HBA, HNA, TA, BP, and APAP, such as described in U.S. Pat.No. 5,508,374 to Lee et al. Compounding is performed using an 18-mmsingle screw extruder. Parts are injection molded the samples intoplaques (60 mm×60 mm).

TABLE 1 Sample 1 2 LCP 47.2 43.2 Epoxy-Functionalized Olefin Copolymer —4.0 Lubricant 0.3 0.3 FC-4400 0.8 0.8 Black Color Masterbatch 12.5 12.5Barium Sulfate 40 40

The molded parts are also tested for thermal and mechanical properties.The results are set forth below in Table 2.

TABLE 2 Sample 1 2 MV1000 (Pa-s) 18 32 MV400 (Pa-s) 27 51 Melting Temp(° C.) (1^(st) Heat) 327 331 DTUL @ 1.8 MPa (° C.) 221 219 CharpyNotched (kJ/m²) 6 8 Tensile Strength (MPa) 115 106 Tensile Modulus (MPa)8,165 6,992 Tensile Elongation at Break (%) 3.5 4.4 Flexural Strength(MPa) 131 107 Flexural Modulus (MPa) 8,718 7,191 Rockwell Hardness(M-scale) 58 38 Shrinkage in the Length Direction (S_(F)) (%) 0.24 0.25Shrinkage in the Width Direction (S_(T)) (%) 0.93 0.94 DimensionalStability 4 4

Example 2

Samples 3-4 are formed from various percentages of a liquid crystallinepolymer, calcium pyrophoshpate, epoxy-functionalized olefin copolymer,lubricant (Glycolube™ P), and black color masterbatch, as indicated inTable 3 below. The epoxy-functionalized olefin copolymer is a terpolymerformed from ethylene, butyl acrylate, and glycidyl methacrylate(Elvaloy® PTW, DuPont). The calcium pyrophosphate has a median particlesize of about 6 micrometers. The black color masterbatch contains 80 wt.% liquid crystalline polymer and 20 wt. % carbon black. The liquidcrystalline polymer in each of the samples is formed from HBA, HNA, TA,BP, and APAP, such as described in U.S. Pat. No. 5,508,374 to Lee et al.Compounding is performed using an 18-mm single screw extruder. Parts areinjection molded the samples into plaques (60 mm×60 mm).

TABLE 3 Sample 3 4 LCP 47.2 43.2 Epoxy-Functionalized Olefin Copolymer —4.0 Lubricant 0.3 0.3 Black Color Masterbatch 12.5 12.5 CalciumPyrophosphate 40 40

The molded parts are also tested for thermal and mechanical properties.The results are set forth below in Table 4.

TABLE 4 Sample 3 4 MV1000 (Pa-s) 40 92 MV400 (Pa-s) 54 135 Melting Temp(° C.) (1^(st) Heat) 329 331 DTUL @ 1.8 MPa (° C.) 220 207 CharpyNotched (kJ/m²) 5 9 Tensile Strength (MPa) 102 97 Tensile Modulus (MPa)8,374 7,016 Tensile Elongation at Break (%) 4.0 5.4 Flexural Strength(MPa) 124 114 Flexural Modulus (MPa) 8,878 8,317 Rockwell Hardness(M-scale) 62 41

These and other modifications and variations of the present inventionmay be practiced by those of ordinary skill in the art, withoutdeparting from the spirit and scope of the present invention. Inaddition, it should be understood that aspects of the variousembodiments may be interchanged both in whole or in part. Furthermore,those of ordinary skill in the art will appreciate that the foregoingdescription is by way of example only, and is not intended to limit theinvention so further described in such appended claims.

What is claimed is:
 1. A polymer composition comprising: 100 parts byweight of at least one liquid crystalline polymer; from about 50 toabout 90 parts by weight of an inorganic particulate material having ahardness value of about 2.5 or more based on the Mohs hardness scale anda median particle size of from about 0.1 to about 35 micrometers; andfrom about 1 to about 15 parts by weight of an epoxy-functionalizedolefin copolymer.
 2. The polymer composition of claim 1, wherein liquidcrystalline polymers constitute from about 20 wt. % to about 80 wt. % ofthe polymer composition.
 3. The polymer composition of claim 1, whereinthe liquid crystalline polymer contains repeating units derived fromterephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid,4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, hydroquinone,4,4′-biphenol, acetaminophen, or a combination thereof.
 4. The polymercomposition of claim 1, wherein the inorganic particulate materialincludes calcium pyrophosphate, calcium sulfate, barium sulfate, or acombination thereof.
 5. The polymer composition of claim 1, wherein theinorganic particulate material constitutes from about 20 wt. % to about60 wt. % of the polymer composition and the epoxy-functionalizedcopolymer constitutes from about 1 wt. % to about 20 wt. % of thepolymer composition.
 6. The polymer composition of claim 1 wherein theepoxy-functionalized olefin copolymer contains an ethylene monomericunit.
 7. The polymer composition of claim 1, wherein theepoxy-functionalized olefin copolymer contains an epoxy-functional(meth)acrylic monomeric component.
 8. The polymer composition of claim7, wherein the epoxy-functional (meth)acrylic monomeric component isderived from glycidyl acrylate, glycidyl methacrylate, or a combinationthereof.
 9. The polymer composition of claim 7, wherein theepoxy-functional (meth)acrylic monomeric unit constitutes from about 1wt. % to about 20 wt. % of the copolymer.
 10. The polymer composition ofclaim 1, wherein the epoxy-functionalized olefin copolymer contains a(meth)acrylic monomeric unit that is not epoxy-functional.
 11. Thepolymer composition of claim 1, wherein the epoxy-functionalized olefincopolymer exhibits a melt flow rate of from about 1 to about 30 gramsper 10 minutes, as determined in accordance with ASTM D1238-13 at a loadof 2.16 kg and temperature of 190° C.
 12. The polymer composition ofclaim 1, wherein the epoxy-functionalized olefin polymer ispoly(ethylene-co-butylacrylate-co-glycidyl methacrylate).
 13. Thepolymer composition of claim 1, further comprising an electricallyconductive filler.
 14. The polymer composition of claim 13, wherein theelectrically conductive filler includes an ionic liquid.
 15. The polymercomposition of claim 1, wherein the composition contains no more thanabout 10 wt. % of fibrous fillers.
 16. The polymer composition of claim1, wherein the composition exhibits a tensile elongation at break ofabout 3.5% or more, as determined in accordance with ISO Test No.527:2012 at 23° C.
 17. The polymer composition of claim 1, wherein thecomposition exhibits a Charpy notched impact strength of about 6 kJ/m²or more, as determined in accordance with ISO Test No. 179-1:2010 at 23°C.
 18. The polymer composition of claim 1, wherein the compositionexhibits a dimensional stability of about 6 or less as determined inaccordance with ISO 294-4:2001 using a Type D2 specimen.
 19. A moldedpart comprising the polymer composition of claim
 1. 20. A molded partfor a camera module, wherein the molded part comprises a polymercomposition that includes a liquid crystalline polymer, the compositionexhibiting a tensile elongation at break of about 3.5% or more asdetermined in accordance with ISO Test No. 527:2012 at 23° C., a Charpynotched impact strength of about 6 kJ/m² or more as determined inaccordance with ISO Test No. 179-1:2010 at 23° C., and a dimensionalstability of about 6 or less as determined in accordance with ISO294-4:2001 using a Type D2 specimen.
 21. The molded part of claim 20,wherein the polymer composition comprises an inorganic particulatematerial having a hardness value of about 2.5 or more based on the Mohshardness scale.
 22. The molded part of claim 21, wherein the inorganicparticulate material has a median size of from about 0.1 to about 35micrometers.
 23. The molded part of claim 20, wherein the polymercomposition comprises an epoxy-functionalized olefin copolymer.
 24. Acamera module comprising the molded part of claim
 19. 25. The cameramodule of claim 24, wherein the camera module comprises a generallyplanar base on which is mounted a carrier assembly, wherein the base,carrier assembly, or both contain the molded part.
 26. A method forjoining the molded part of claim 19 to an additional component, whereinthe method comprises: forming receiving holes in the molded part and thecomponent; inserting heat stakes into the holes; and subjecting the heatstakes to heat and pressure to thereby join the molded part to thecomponent.